UNITED MICROELECTRONICS (NYSE: UMC) SVP Oliver Chang discloses 4,819,289-share stake

Rhea-AI Filing Summary

UNITED MICROELECTRONICS CORP senior vice president Oliver Chang filed an initial Form 3 showing direct ownership of 4,819,289 Common Shares. This holding includes 1,270,000 shares of Restricted Stock Award (RSA), with a specified portion scheduled to vest each year on December 5 from 2026 through 2029. The filing records Chang’s starting equity position as an officer rather than any new share purchase or sale.

Insider Trade Summary

1 transaction reported

Mixed 1 txn

Insider CHANG OLIVER

Role SVP

Type	Security	Shares	Price	Value
holding	Common Shares	--	--	--

Holdings After Transaction: Common Shares — 4,819,289 shares (Direct, null)

Footnotes (1)

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Key Figures

Common Shares held: 4,819,289 shares Restricted Stock Awards: 1,270,000 shares RSA vesting period start: December 5, 2026 +1 more

4 metrics

Common Shares held 4,819,289 shares Total Common Shares directly owned following the reported holding entry

Restricted Stock Awards 1,270,000 shares Portion of holdings designated as Restricted Stock Award (RSA)

RSA vesting period start December 5, 2026 Annual vesting of RSA shares begins on this date

RSA vesting period end December 5, 2029 Annual vesting of RSA shares continues through this date

Key Terms

Restricted Stock Award (RSA), Common Shares, Form 3

3 terms

Restricted Stock Award (RSA) financial

"Includes 1,270,000 shares of Restricted Stock Award (RSA) and a specified number"

Common Shares financial

"security_title": "Common Shares""

Common shares are the basic units of ownership in a company that give holders a claim on profits and a right to vote on key matters, like electing the board. Think of them as membership cards in a club: they let you share in successes and losses, but in a bankruptcy or liquidation they are paid after creditors and preferred shareholders, so their value can swing more and matters for assessing risk and potential return.

Form 3 regulatory

"INSIDER FILING DATA (Form 3):"

Form 3 is the initial public filing that officers, directors and large shareholders must submit to report their ownership of a company’s securities when they become insiders. It acts like an opening inventory sheet that gives investors a starting point to see who holds significant stakes and to spot later trades or potential conflicts of interest, helping assess insider confidence and transparency.

Understanding Insider Trading Forms →

SEC Form 3

FORM 3

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

INITIAL STATEMENT OF BENEFICIAL OWNERSHIP OF SECURITIES

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940

OMB APPROVAL

OMB Number:			3235-0104
Estimated average burden
hours per response:			0.5

1. Name and Address of Reporting Person^*

CHANG OLIVER

(Last) (First) (Middle)

8F, NO.68, SEC. 1, NEIHU RD.,

(Street)

TAIPEI TAIWAN 11493

(City) (State) (Zip)

TAIWAN

(Country)

2. Date of Event Requiring Statement (Month/Day/Year)
04/29/2026

3. Issuer Name and Ticker or Trading Symbol
UNITED MICROELECTRONICS CORP [ UMC ]

3a. Foreign Trading Symbol
[2303.TW]

5. If Amendment, Date of Original Filed (Month/Day/Year)

4. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	SVP

6. Individual or Joint/Group Filing (Check Applicable Line)

X	Form filed by One Reporting Person
	Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Beneficially Owned
1. Title of Security (Instr. 4)	2. Amount of Securities Beneficially Owned (Instr. 4)	3. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	4. Nature of Indirect Beneficial Ownership (Instr. 5)
Common Shares	4,819,289(1)	D

Table II - Derivative Securities Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 4)	2. Date Exercisable and Expiration Date (Month/Day/Year)		3. Title and Amount of Securities Underlying Derivative Security (Instr. 4)		4. Conversion or Exercise Price of Derivative Security	5. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	6. Nature of Indirect Beneficial Ownership (Instr. 5)
	Date Exercisable	Expiration Date	Title	Amount or Number of Shares

Explanation of Responses:

1. Includes 1,270,000 shares of Restricted Stock Award (RSA) and a specified number of shares subject to the RSA will vest annually on December 5 from 2026 to 2029.

Remarks:

Exhibit List Exhibit 24: Power of Attorney

	/s/Chitung Liu, attorney-in-fact	05/07/2026
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 5 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.
* Form 3: SEC 1473 (03-26)

FAQ

What does Oliver Chang’s Form 3 filing for UMC show?

The Form 3 shows that SVP Oliver Chang directly holds 4,819,289 Common Shares of UNITED MICROELECTRONICS CORP (UMC). This initial statement records his starting equity position as an officer, rather than reporting any recent share purchases or sales.

How many UNITED MICROELECTRONICS (UMC) shares does Oliver Chang report owning?

Oliver Chang reports direct ownership of 4,819,289 Common Shares of UNITED MICROELECTRONICS CORP. This figure represents his beneficial holdings as disclosed in the Form 3 and forms the baseline for tracking any future insider transactions in UMC stock.

What portion of Oliver Chang’s UMC stake is Restricted Stock Awards (RSA)?

The filing states that Chang’s holdings include 1,270,000 shares of Restricted Stock Award (RSA). These RSAs are part of his total 4,819,289-share position and represent stock granted subject to vesting conditions over several future years.

What is the vesting schedule for Oliver Chang’s Restricted Stock Awards at UMC?

The Form 3 footnote explains that a specified number of shares under the Restricted Stock Award (RSA) will vest annually on December 5 from 2026 through 2029. This means the RSA grant converts into fully owned shares gradually over four years.

Does Oliver Chang’s UMC Form 3 indicate recent buying or selling of shares?

No transaction activity is indicated; the entry is classified as a holding with an unknown transaction code. The Form 3 serves as an initial beneficial ownership report, establishing Chang’s 4,819,289-share position rather than documenting any new purchase or sale.